WO2015188578A1

WO2015188578A1 - Nonlinear system distortion correction device and method

Info

Publication number: WO2015188578A1
Application number: PCT/CN2014/090401
Authority: WO
Inventors: 王蕾; 戴征坚; 潘卫明; 张哲�; 黄梅
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-06-13
Filing date: 2014-11-05
Publication date: 2015-12-17
Also published as: US9973221B2; EP3145140A1; CN105227507A; CN105227507B; EP3145140A4; US20170117927A1

Abstract

Disclosed are a nonlinear system distortion correction device and method. The device comprises: a robustness signal source generator configured to generate a robustness signal provided for an adaptor; the adaptor configured to collect a main link signal output by a signal generator and a feedback signal of the main link signal returned by a feedback link, and generate a correction parameter according to the main link signal, the feedback signal and the robustness signal; and a pre-corrector configured to conduct pre-correction processing on the main link signal output by the signal generator according to the correction parameter. By means of the present invention, by providing a robustness signal, it is guaranteed that a system will not bring the problem of unknowable abrupt change of power or abnormal output frequency spectrum after an actual link signal passes through a pre-distortion module due to the fact that the difference between a former configured signal characteristic and the latter one is too large under various dynamic configurations, thereby enhancing the robustness of the system in a dynamic operating condition, so that various frequency band configuration requirements of an operator and dynamic change requirements of telephone traffic in different regions can be satisfied.

Description

Nonlinear system distortion correcting device and method

Technical field

The present invention relates to the field of communication technologies, and in particular, to a nonlinear system distortion correction apparatus and method.

Background technique

With the development of mobile communications, spectrum resources are becoming scarcer, and operators often find it difficult to get enough bandwidth in one frequency band. In the future, various operators will establish cross-band communication systems more and more frequently. This will result in the communication device system needing to handle ultra-wideband signals across the band. At the same time, operators' requirements for CAPEX (Capital Expenditure) and OPEX (Operation Expense) will become more and more important considerations when selecting equipment. For the wireless communication base station system, about 80% of the power consumption is generated by the radio power amplifier (PA, PowerAmplifier) in the RRU (Radio Remote Unit) module, so with the development of digital mobile communication technology, the high efficiency power amplifier (hereinafter referred to as power amplifier) has become a requirement that must be met by major system equipment manufacturers. A major problem facing high-efficiency power amplifiers is the interfering interference that occurs when modern power-efficient modulation schemes operate the power amplifier close to the saturation region, which causes the power amplifier to produce severe nonlinear distortion. Digital predistortion technology has become a basic power amplifier linearization function module of the RRU system in current mainstream communication equipment. Based on the above information, the digital pre-distortion technology in the RRU needs to cope with ultra-wideband signals across the band under current operating conditions.

This situation poses a challenge to systems that use power amplifier linearization techniques. The current digital predistortion techniques are based on off-line adaptive iterative techniques, where digital predistortion information can't always follow the actual link changes. This problem is particularly prominent in the configuration of ultra-wideband signals across frequency bands. For example, the actual test can be found in TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) signal and TDD-LTE (Time Division Duplexing-Time Division Long Term Evolution, time division duplex - Time-division long-term evolution) Signal mixed-mode cross-band application, under certain configuration conditions, when the cell is initially built, because the service time slot of a certain frequency band has no service, the predistorter is set to extract the linearization parameter data is single-band, when When there are many services in this frequency band, the predistorter can not update the linearization parameters in real time. Actually, the linearization parameters of the cross-band signals are extracted through the single-band, and the output power will be abruptly changed by more than ten dB. The spectrum is abnormal, which is easy to cause the system's power amplifier. Damage is a great hazard to the stability of the system.

Summary of the invention

Embodiments of the present invention provide a nonlinear system distortion correction apparatus and method to solve at least the problem of poor system robustness in the prior art.

In order to solve the above technical problem, in one aspect, the present invention provides a nonlinear system distortion correction apparatus, including:

a robust signal source generator configured to generate a robustness signal provided to the adaptor;

An adaptor configured to acquire a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generate a correction according to the main link signal, the feedback signal, and the robustness signal parameter;

The pre-corrector is configured to perform pre-correction processing on the main link signal output by the signal generator according to the correction parameter.

Further, the adaptor includes:

a data acquisition unit configured to acquire a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link;

a matrix synthesis unit configured to generate a linearization parameter extraction matrix Rr and a target matrix Zr according to the main link signal and the feedback signal; and generate a linearization parameter extraction matrix Rs and a target matrix Zs according to the robustness signal; for Rs, Zs Matrix synthesis with Rr, Zr, to obtain matrices R and Z;

The correction parameter generation unit is configured to extract a linearization parameter according to the matrices R and Z, and load the linearization parameter as a correction parameter into the pre-corrector.

Further, the pre-corrector includes:

An index address obtaining unit is configured to calculate an amplitude or a power of the main link signal to obtain an index address of the correction signal;

a correction signal acquisition unit, configured to search a corresponding lookup table according to the index address, and generate a correction signal according to the content of the lookup table;

The pre-correction processing unit is configured to perform pre-correction processing on the main link signal output by the signal generator according to the correction signal and the correction parameter.

Further, the pre-correction processing unit performs pre-correction processing according to formulas (1), (2), and (3):

y(n)=F _U,X (U,X) (1)

U=[U(n), U(n-1),...,U(n-K)] (2)

X=[x(n),x(n-1),...,x(n-J)] (3)

Where y is the pre-corrected signal; n is the signal sampling time sequence number; F _{U, X} (·) is the pre-correction function, and the correction parameter is the coefficient in the pre-correction function F _{U, X} (·); U is the The vector of the correction signal; X is the vector of the main link signal; K is the maximum delay of the correction signal; J is the maximum delay of the main link signal.

Further, the matrix synthesis unit performs matrix synthesis using equations (4) and (5):

R=a×Rs+b×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.

Further, the robustness signal generator generates a robustness signal including:

The baseband signal is subjected to frequency conversion, filtering and frequency shift processing to obtain a main link signal, and data characteristics processing is performed on the main link signal to obtain a robust signal.

Further, after acquiring the primary link signal and the feedback signal, the adaptor performs data characteristic processing on the primary link signal and the feedback signal.

Further, the data characteristic processing refers to an operation of delay alignment and energy alignment on the collected signals.

Further, the device further includes:

a digital to analog converter configured to convert the digital signal output by the precorrector into an analog signal;

a nonlinear system configured to perform nonlinear processing on the analog signal;

The analog-to-digital converter is configured to couple out a signal in a signal output by the nonlinear system, convert it into a digital signal, and input it as a feedback signal to the adaptor.

In another aspect, the present invention also provides a nonlinear system distortion correction method, including:

Generating a robustness signal to the adaptor;

Acquiring a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generating a correction parameter according to the main link signal, the feedback signal, and the robustness signal;

A pre-correction process is performed on the main link signal output from the signal generator based on the correction parameter.

Further, generating calibration parameters specifically includes:

Acquiring a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link;

Generating a linearization parameter extraction matrix Rr and a target matrix Zr according to the main link signal and the feedback signal; and generating a linearization parameter extraction matrix Rs and a target matrix Zs according to the robustness signal; and performing matrix on Rs, Zs, and Rr, Zr Synthesis, to obtain matrices R and Z;

According to the matrices R and Z, linearization parameters are extracted, and the linearization parameters are loaded as correction parameters into the pre-corrector.

Further, the pre-correction process specifically includes:

Calculating the amplitude or power of the primary link signal to obtain an index address of the corrected signal;

Finding a corresponding lookup table according to the index address, and generating a correction signal according to the content of the lookup table;

A pre-correction process is performed on the main link signal output from the signal generator based on the correction signal and the correction parameter.

Further, pre-correction processing is performed according to formulas (1), (2), and (3):

_{y (n) = F U,} X (U, X) (1)

U=[U(n), U(n-1),...,U(n-K)] (2)

X={x(n), x(n-1),...,x(n-J)] (3)

Further, matrix synthesis is performed using equations (4) and (5):

R=a×Rs+b×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.

Further, generating robustness signals includes:

Further, after collecting the primary link signal and the feedback signal, the method further includes:

Data characteristic processing is performed on the primary link signal and the feedback signal.

Further, converting the pre-corrected digital signal into an analog signal;

Performing nonlinear processing on the analog signal;

A path is coupled in the nonlinearly processed signal, converted into a digital signal and returned as a feedback signal.

The beneficial effects of the present invention are as follows:

By providing a robust signal, the invention ensures that the system does not have a large difference between the signal characteristics of the former configuration and the latter one under various dynamic configurations, so that the actual link signal passes through the predistortion module. The problem of abrupt power abrupt or abnormal output spectrum greatly improves the robustness of the system under dynamic operation, and can meet the operator's various frequency band configuration requirements and the dynamic changes of traffic volume in different regions.

DRAWINGS

1 is a schematic structural diagram of a nonlinear system distortion correcting apparatus according to an embodiment of the present invention;

2 is a schematic structural diagram of another nonlinear system distortion correcting apparatus according to an embodiment of the present invention;

3 is a schematic structural diagram of an adaptor in an embodiment of the present invention;

4 is a schematic structural diagram of a pre-corrector in an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of still another nonlinear system distortion correcting apparatus according to an embodiment of the present invention; FIG.

6 is a flow chart of a nonlinear system distortion correction method in an embodiment of the present invention.

detailed description

The invention will be further described in detail below with reference to the drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a general device and a method for improving the robustness of a system using a power amplifier linearization technique, and adopts a method of adding a robust signal source to a linear pre-distortion self-iterative system to participate in linearization coefficient extraction, thereby solving the cross-band ultra-wideband. In some configurations, the predistortion system in the predistortion system causes the system output power to be unstable, which may cause problems such as successful damage and abnormal signal spectrum.

As shown in FIG. 1 , an embodiment of the present invention relates to a nonlinear system distortion correction apparatus, including:

The adaptor is configured to collect a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generate a correction parameter according to the main link signal, the feedback signal, and the robustness signal;

Further, as shown in FIG. 2, the nonlinear system distortion correction apparatus according to the embodiment of the present invention may further include:

a digital-to-analog converter (DAC), configured to convert a digital signal output by the pre-corrector into an analog signal;

a nonlinear system configured to perform nonlinear processing on analog signals;

An analog-to-digital converter (ADC) is configured to couple a signal in a signal output from a nonlinear system, convert it into a digital signal, and input it as a feedback signal to the adaptor.

The robust signal source generator performs up-conversion and filtering on the baseband signal, and then performs frequency shift processing according to the configuration of the system requirements, and obtains a main link signal consistent with the required bandwidth and configuration of the system, and collects the main link signal. And performing data characteristic processing, wherein the data characteristic processing process is consistent with the data characteristic processing in the adaptor. The processed signal is stored and supplied to the adaptor call as a robust signal source.

As shown in Figure 3, the adaptor includes:

The data acquisition unit is configured to collect a main link signal (a digital signal in the forward link) output by the signal generator and a feedback signal returned by the main link signal via the feedback link (ie, a digital signal in the feedback link of the power amplifier) );

The signal processing unit is configured to perform data characteristic processing on the collected main link signal and the feedback signal; the data characteristic processing refers to performing delay alignment and energy alignment on the collected signal.

a matrix synthesis unit configured to generate a linearization parameter extraction matrix Rr and a target matrix Zr according to the main link signal and the feedback signal; and generate a linearization parameter extraction matrix Rs and a target matrix Zs according to the robustness signal; and to Rs, Zs, and Rr , Zr performs matrix synthesis to obtain matrices R and Z;

The matrix synthesis unit establishes the distortion model of the nonlinear system, and the distortion model adopts the general memory polynomial model, as follows:

Where S _i is the model input signal; j is the signal delay of the input signal, k is the signal delay of the input signal modulus; p is the model order; J is the maximum signal delay of the input signal, and k is the maximum of the input signal modulus Signal delay; P is the highest order of the model; w _p,k,j is the model coefficient. Corresponding to the present invention, S _i is the output signal of the signal generator module, that is, the main link signal; S _o is the target matrix, that is, the feedback signal.

In order to obtain the correction parameter W, the commonly used solution method is the LS algorithm, which yields:

W=R ^-1 Z (7)

Where R is the parameter extraction matrix; Z is the target matrix, which is the target matrix So in equation (6); W is the correction parameter; (·) ^-1 is the pseudo-inverse operation; the meaning and formula of other expressions (6) ) Consistent.

It should be noted that the parameter extraction matrix Rr and the target matrix Zr corresponding to the main link signal are consistent with the parameter extraction matrix Rs and the target matrix Zs corresponding to the robustness signal source, and are all in accordance with formulas (7) and (8). ) Formula generation.

Here, the derivation formula (8) of R has been given, which is based on the combination of two items in the memory polynomial model (6), and the physical meanings in the formula are already clear.

In matrix synthesis, the matrix synthesis unit performs matrix synthesis using equations (4) and (5):

R=a×Rs+b×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.

The correction parameter generation unit is configured to extract linearization parameters according to the matrices R and Z, and load the linearization parameters as correction parameters into the pre-corrector. Adaptive algorithms are often used, such as Least Squares (Least Squares, LS) algorithm, Recursive Least Squares (RLS) algorithm or Least Mean Square (LMS) algorithm, extract linearization parameters, and download the extracted linearization parameters to the pre-corrector, update the correction The parameters are downloaded to the correction information generating unit.

As shown in Figure 4, the pre-corrector includes:

The index address obtaining unit is configured to calculate the amplitude or power of the main link signal to obtain an index address of the corrected signal. Linear or non-linear mapping (intercepting operation) on the amplitude or power of the input signal, generating address information, addressing, and obtaining an index address.

The correction signal acquisition unit is configured to search the corresponding lookup table (linearized lookup table) according to the index address, and obtain a correction signal according to the content of the lookup table;

The pre-correction processing unit is configured to perform pre-correction processing on the main link signal output by the signal generator according to the correction signal and the correction parameter. Wherein, the pre-correction processing unit performs pre-correction processing according to formulas (1), (2), and (3):

y(n)=F _U,X (U,X) (1)

U=[U(n), U(n-1),...,U(n-K)] (2)

X=[x(n),x(n-1),...,x(n-J)] (3)

Where y is the pre-corrected signal; n is the signal sampling time serial number; F _{U, X} (·) is the pre-correction function, the correction parameter is the coefficient in the pre-correction function F _{U, X} (·); U is the correction signal Vector; X is the vector of the main link signal; K is the maximum delay of the correction signal; J is the maximum delay of the main link signal.

The pre-corrector pre-corrects the main link signal according to the amplitude and phase information of the signal, and the correction information is equal in amplitude and opposite in phase to the distortion signal generated by the nonlinear system, thereby canceling the nonlinear system causing the main link signal Distortion.

The pre-corrected signal is converted from the digital domain to the analog domain by the DAC, and the nonlinear processing of the signal is realized by the nonlinear system. The output signal of the nonlinear system passes through the ADC, and finally the feedback digital signal is obtained. The technical solution of the present invention is not limited to the DAC, the nonlinear system, and the ADC. Therefore, the present invention can be implemented by using the above-mentioned modules. Therefore, the foregoing embodiments of the present invention are not described in detail.

5 is a specific embodiment of a power amplifier pre-correction device (non-linear system distortion correction device), including a signal generator module, a channel filter module, a pre-corrector module, a DAC module, an ADC module, an up-conversion module, and a lower Frequency conversion module, LO (Local Oscillator) module, power amplifier module, attenuator module, adaptive module, robust signal source module. Compared with FIG. 2, in the implementation of the pre-corrector module, the pre-corrected signal is obtained according to the pre-correction function shown in equation (6). In the correction parameter extraction unit of the adaptor module, when constructing the parameter extraction matrix, the parameter extraction matrix R obtained by the current link signal and the robustness signal source is constructed according to equation (8), and finally used to extract the matrix R of the parameters. And Z are constructed according to equations (4) and (5).

As shown in FIG. 6, an embodiment of the present invention further relates to a nonlinear system distortion correction method implemented by the foregoing apparatus, including:

Step S601, generating a robustness signal provided to the adaptor;

Step S602, collecting a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generating a correction parameter according to the main link signal, the feedback signal, and the robustness signal;

Step S603, performing pre-correction processing on the main link signal output by the signal generator according to the correction parameter.

The generating the calibration parameter includes:

Generating a linearization parameter extraction matrix Rs and a target matrix Zs according to the main link signal and the feedback signal; and generating a linearization parameter extraction matrix Rr and a target matrix Zr according to the robustness signal; and performing matrix on Rs, Zs, and Rr, Zr Synthesis, to obtain matrices R and Z;

The pre-correction process specifically includes:

Pre-correcting the main link signal output by the signal generator according to the correction signal and the correction parameter; this step performs pre-correction processing according to formulas (1), (2) and (3):

y(n)=F _U,X (U,X) (1)

U=[U(n), U(n-1),...,U(n-K)] (2)

X=[x(n),x(n-1),...,x(n-J)] (3)

Matrix synthesis using equations (4) and (5):

R=a×Rssb×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.

Generating robustness signals include:

The baseband signal is subjected to frequency conversion, filtering and frequency shift processing to obtain a main link signal, and data characteristics processing is performed on the main link signal to obtain a robust signal. In addition, after the main link signal and the feedback signal are acquired, data characteristic processing is also performed on the main link signal and the feedback signal. Data characteristic processing refers to the operation of delay alignment and energy alignment of the acquired signals.

Converting the pre-corrected digital signal into an analog signal;

Performing nonlinear processing on the analog signal;

The technical solution of the present invention is not limited to TD-SCDMA and TDL-LTE mixed mode cross-band ultra-wideband RRU system applications, for GSM (Global System for Mobile communication), CDMA (Code Division Multiple Access), code division multiple access ), UMTS (Universal Mobile Telecommunications System), FDD-LTE (Frequency Division Duplexing-Long Term Evolution) and WiMAX (Worldwide Interoperability for Microwave Access) The single-mode or mixed-mode system also has the same effect of improving the robustness of the system using the power amplifier linearization technique. The technical solution of the present invention has no specific requirements for signal modulation mode and bandwidth, and is generally applicable to the improvement of the robustness of various systems using the power amplifier linearization technology, and the robustness is obviously superior to the traditional system using the power amplifier linearization technology. Improve the work security and performance robustness of the communication system and even the entire wireless base station system.

While the preferred embodiments of the present invention have been disclosed for purposes of illustration, those skilled in the art will recognize that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above.

Industrial applicability

As described above, a nonlinear system distortion correction apparatus and method provided by an embodiment of the present invention has the following beneficial effects: by providing a robustness signal, it is ensured that the system does not have the former configuration under various dynamic configurations. The difference between the signal characteristics and the latter is too large, causing the actual link signal to pass through the predistortion module, causing an agnostic power abrupt or output spectrum anomaly, which greatly improves the robustness of the system under dynamic operation and can satisfy the operation. The various frequency band configuration requirements of the quotient and the dynamic changes of traffic volume in different regions.

Claims

A nonlinear system distortion correction device includes:

a robust signal source generator configured to generate a robustness signal provided to the adaptor;

An adaptor configured to acquire a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generate a correction according to the main link signal, the feedback signal, and the robustness signal parameter;

The pre-corrector is configured to perform pre-correction processing on the main link signal output by the signal generator according to the correction parameter.
The nonlinear system distortion correcting apparatus according to claim 1, wherein said adaptor comprises:

a data acquisition unit configured to acquire a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link;

a matrix synthesis unit configured to generate a linearization parameter extraction matrix Rr and a target matrix Zr according to the main link signal and the feedback signal; and generate a linearization parameter extraction matrix Rs and a target matrix Zs according to the robustness signal; for Rs, Zs Matrix synthesis with Rr, Zr, to obtain matrices R and Z;

The correction parameter generation unit is configured to extract a linearization parameter according to the matrices R and Z, and load the linearization parameter as a correction parameter into the pre-corrector.
The nonlinear system distortion correcting apparatus according to claim 1 or 2, wherein said pre-corrector comprises:

An index address obtaining unit is configured to calculate an amplitude or a power of the main link signal to obtain an index address of the correction signal;

a correction signal acquisition unit, configured to search a corresponding lookup table according to the index address, and generate a correction signal according to the content of the lookup table;

The pre-correction processing unit is configured to perform pre-correction processing on the main link signal output by the signal generator according to the correction signal and the correction parameter.
The nonlinear system distortion correcting apparatus according to claim 3, wherein said pre-correction processing unit performs pre-correction processing according to formulas (1), (2), and (3):

y(n)=F U,X (U,X)

(1)

U=[U(n), U(n-1),...,U(n-K)]

(2)

X=[x(n),x(n-1),...,x(n-J)]

(3)

Where y is the pre-corrected signal; n is the signal sampling time sequence number; F U, X (·) is the pre-correction function, and the correction parameter is the coefficient in the pre-correction function F U, X (·); U is the The vector of the correction signal; X is the vector of the main link signal; K is the maximum delay of the correction signal; J is the maximum delay of the main link signal.
The nonlinear system distortion correcting apparatus according to claim 2, wherein said matrix synthesis unit performs matrix synthesis using equations (4) and (5):

R=a×Rs+b×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.
The nonlinear system distortion correction apparatus of claim 1, wherein the robustness signal source generator generates a robustness signal comprising:

The baseband signal is subjected to frequency conversion, filtering and frequency shift processing to obtain a main link signal, and data characteristics processing is performed on the main link signal to obtain a robust signal.
The nonlinear system distortion correcting apparatus according to claim 6, wherein said adaptor acquires said main link signal and said feedback signal, and performs data characteristics on said main link signal and said feedback signal deal with.
The nonlinear system distortion correcting apparatus according to claim 7, wherein said data characteristic processing refers to an operation of delay-aligning and energy-aligning the collected signals.
The non-linear system distortion correction device of claim 1, 2, 4, 5, or 8, wherein the device further comprises:

a digital to analog converter configured to convert the digital signal output by the precorrector into an analog signal;

a nonlinear system configured to perform nonlinear processing on the analog signal;

The analog-to-digital converter is configured to couple out a signal in a signal output by the nonlinear system, convert it into a digital signal, and input it as a feedback signal to the adaptor.
A nonlinear system distortion correction method includes:

Generating a robustness signal to the adaptor;

Acquiring a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link, and generating a correction parameter according to the main link signal, the feedback signal, and the robustness signal;

A pre-correction process is performed on the main link signal output from the signal generator based on the correction parameter.
The nonlinear system distortion correction method according to claim 10, wherein the generating the correction parameter comprises:

Acquiring a main link signal output by the signal generator and a feedback signal returned by the main link signal via the feedback link;

Generating a linearization parameter extraction matrix Rs and a target matrix Zs according to the main link signal and the feedback signal; and generating a linearization parameter extraction matrix Rr and a target matrix Zr according to the robustness signal; and performing matrix on Rs, Zs, and Rr, Zr Synthesis, to obtain matrices R and Z;

According to the matrices R and Z, linearization parameters are extracted, and the linearization parameters are loaded as correction parameters into the pre-corrector.
The nonlinear system distortion correction method according to claim 10 or 11, wherein the pre-correction processing specifically comprises:

Calculating the amplitude or power of the primary link signal to obtain an index address of the corrected signal;

Finding a corresponding lookup table according to the index address, and generating a correction signal according to the content of the lookup table;

A pre-correction process is performed on the main link signal output from the signal generator based on the correction signal and the correction parameter.
The nonlinear system distortion correction method according to claim 12, wherein the pre-correction processing is performed according to the formulas (1), (2), and (3):

y(n)=F U,X (U,X)

(1)

U=[U(n), U(n-1),...,U(n-K)]

(2)

X=[x(n),x(n-1),...,x(n-J)]

(3)

Where y is the pre-corrected signal; n is the signal sampling time sequence number; F U, X (·) is the pre-correction function, and the correction parameter is the coefficient in the pre-correction function F U, X (·); U is the The vector of the correction signal; X is the vector of the main link signal; K is the maximum delay of the correction signal; J is the maximum delay of the main link signal.
The nonlinear system distortion correction method according to claim 11, wherein the matrix synthesis is performed using the formula (4) (5):

R=a×Rs+b×Rr (4)

Z=a×Zs+b×Zr (5)

Among them, a and b are weighting coefficients.
The nonlinear system distortion correction method of claim 10, wherein generating the robustness signal comprises:

The baseband signal is subjected to frequency conversion, filtering and frequency shift processing to obtain a main link signal, and data characteristics processing is performed on the main link signal to obtain a robust signal.
The non-linear system distortion correction method of claim 15, wherein after the collecting the main link signal and the feedback signal, the method further comprises:

Data characteristic processing is performed on the primary link signal and the feedback signal.
The nonlinear system distortion correction method according to claim 16, wherein said data characteristic processing refers to an operation of delay-aligning and energy-aligning the acquired signals.
The nonlinear system distortion correction method according to claim 10, 11, 13, 14 or 17, wherein

Converting the pre-corrected digital signal into an analog signal;

Performing nonlinear processing on the analog signal;

A path is coupled in the nonlinearly processed signal, converted into a digital signal and returned as a feedback signal.